Divided phase AC synchronous motor controller

ABSTRACT

A circuit includes phase windings, a direct current (DC) power supply, and a power switch circuit. The power switch circuit includes at least one power switch. The circuit also includes a control circuit to control the power switch circuit. The control circuit includes a logic control shut off circuit to shut off the control circuit when the motor is at synchronous speed. The circuit also includes at least one non-collapsing DC power supply component to prevent the DC power supply from collapsing when the at least one power switch is on and conducting during at least a portion of a cycle. One or more of the DC power supply and power switch circuit may be at a midpoint of the phase windings.

RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/080,785, entitled Divided Phase AC Synchronous Motor Controller,filed Nov. 14, 2013, which claims priority to U.S. Patent App. Ser. No.61/726,550, entitled Divided Phase AC Synchronous Motor Controller,filed Nov. 14, 2012, the entire contents of which are incorporatedherein by reference.

FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable.

COMPACT DISK APPENDIX

Not Applicable.

BACKGROUND

In view of the growing proliferation of environmentally friendly laws,enhancements to various classes of motors are required. For example,refrigeration fan motors in a low wattage range, e.g. 4 to 16 watts,used in both the commercial and residential refrigeration markets, havetraditionally been low efficiency, such as around 12%-26% efficient. Itwould be desirable to provide technologies to address enhancementsrequired in different classes of motors.

SUMMARY

A divided phase windings circuit includes divided phase windings, apower switch circuit comprising at least one power switch at a midpointof the divided phase windings, a direct current (DC) supply circuit atthe midpoint of the divided phase windings, and one or morenon-collapsing DC power supply components to prevent the DC power supplyfrom collapsing when the at least one power switch is on and conducting.

A circuit for a motor comprises phase windings divided at leastapproximately in half. The circuit includes a direct current (DC) powersupply at least approximately at a midpoint of the phase windings toreceive alternating current (AC) power from the phase windings andconvert the AC power to DC power and a power switch circuit comprisingat least one power switch at least approximately at the midpoint of thephase windings to receive AC power from the phase windings. The circuitalso includes a control circuit to control the power switch circuit,wherein the control circuit comprises a logic control shut off circuitto shut off the control circuit when the motor is at synchronous speed.The circuit also includes at least one non-collapsing DC power supplycomponent connected to the DC power supply to prevent the DC powersupply from collapsing when the at least one power switch is on andconducting during at least a portion of an AC cycle.

In another aspect, a circuit for a motor comprises phase windings and adirect current (DC) power supply at a midpoint of the phase windings.The circuit includes a power switch circuit comprising at least onepower switch at the midpoint of the phase windings and a control circuitto control the power switch circuit, wherein the control circuitcomprises a logic control shut off circuit to shut off the controlcircuit when the motor is at synchronous speed. The circuit alsoincludes at least one non-collapsing DC power supply component toprevent the DC power supply from collapsing when the at least one powerswitch is on and conducting during at least a portion of a cycle.

In another aspect, a circuit for a motor comprises phase windings toreceive alternating current (AC) power and a direct current (DC) powersupply between the phase windings to receive the AC power from the phasewindings and convert the AC power to a DC power. The circuit includes apower switch circuit comprising at least one power switch between thephase windings and a control circuit to control the power switchcircuit, wherein the control circuit comprises a logic control shut offcircuit to shut off the control circuit when the motor is at synchronousspeed. The circuit also includes at least one non-collapsing DC powersupply component to prevent the DC power supply from collapsing when theat least one power switch is on and conducting during at least a portionof a cycle.

A method for a circuit for a motor comprises providing phase windingsdivided at least approximately in half and providing a direct current(DC) power supply at least approximately at a midpoint of the phasewindings to receive alternating current (AC) power from the phasewindings and convert the AC power to DC power. The method includesproviding a power switch circuit comprising at least one power switch atleast approximately at the midpoint of the phase windings to receive ACpower from the phase windings. The method also includes providing acontrol circuit to control the power switch circuit, wherein the controlcircuit comprises a logic control shut off circuit to shut off thecontrol circuit when the motor is at synchronous speed. The method alsoincludes providing at least one non-collapsing DC power supply componentconnected to the DC power supply to prevent the DC power supply fromcollapsing when the at least one power switch is on and conductingduring at least a portion of an AC cycle.

In another aspect, a method for a circuit for a motor comprisesproviding phase windings and providing a direct current (DC) powersupply at a midpoint of the phase windings. The method includesproviding a power switch circuit comprising at least one power switch atthe midpoint of the phase windings and providing a control circuit tocontrol the power switch circuit, wherein the control circuit comprisesa logic control shut off circuit to shut off the control circuit whenthe motor is at synchronous speed. The method also includes providing atleast one non-collapsing DC power supply component to prevent the DCpower supply from collapsing when the at least one power switch is onand conducting during at least a portion of a cycle.

In another aspect, a method for a circuit for a motor comprisesproviding phase windings to receive alternating current (AC) power andproviding a direct current (DC) power supply between the phase windingsto receive the AC power from the phase windings and convert the AC powerto a DC power. The method includes providing a power switch circuitcomprising at least one power switch between the phase windings andproviding a control circuit to control the power switch circuit, whereinthe control circuit comprises a logic control shut off circuit to shutoff the control circuit when the motor is at synchronous speed. Themethod also includes providing at least one non-collapsing DC powersupply component to prevent the DC power supply from collapsing when theat least one power switch is on and conducting during at least a portionof a cycle.

The phase windings may be divided in half or in other portions orotherwise distributed and may be, for example, bifilar or lap wound. Thenon-collapsing DC power supply components may include one or more of atap from the phase windings electrically connected to the DC powersupply, a secondary phase coil winding connected to the DC power supplyto power the power supply, one or more resistors between the phasewindings and the power switch circuit, one or more Zener diodes betweenthe phase windings and the power switch circuit, and/or one or moreelectrical components to create a voltage drop between the phasewindings and the power switch circuit to prevent the power supply fromcollapsing when the at least one power switch in the power switchcircuit is on and conducting.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts motor phase windings divided with a control circuitlocated at a mid-point in the motor phase windings.

FIG. 2 depicts a single phase electronically commutated motor (ECM).

FIG. 3 depicts a divided phase winding circuit.

FIG. 4 depicts a divided phase winding circuit with a tap from thedivided phase winding coil to the direct current (DC) power supply.

FIG. 5 depicts a divided phase winding circuit with resisters betweenthe divided phase windings and the power switch(es).

FIG. 6 depicts a divided phase winding circuit with a secondary coil.

FIG. 7 depicts a control of phase current direction during start up andcontinuous operation below synchronous speeds in a divided phase windingcircuit.

FIG. 8 depicts a control of phase current direction at a synchronousspeed of 1800 revolutions per minute (RPM) in a four pole divided phasewinding circuit.

FIG. 9 depicts a control of phase current direction at a synchronousspeed of 3600 revolutions per minute (RPM) in a two pole divided phasewinding circuit.

FIG. 10 depicts DC supply storage capacitor charging periods.

FIG. 11 depicts a divided phase winding circuit with a secondary coiland one power switch.

FIG. 12 depicts a divided phase winding circuit with a secondary coiland one power switch.

FIGS. 13 and 13A depict a divided phase winding circuit with a secondarycoil and one power switch.

FIG. 14 depicts a divided phase winding circuit with two power switches.

FIG. 15 depicts a divided phase winding circuit with one power switch.

FIG. 16 depicts a divided phase winding circuit with two power switchesin series.

FIG. 17 depicts a divided phase winding circuit with a tap from thedivided phase winding coil to the direct current (DC) power supply andtwo power switches in series.

FIG. 18 depicts a divided phase winding circuit with two power switchesin parallel.

FIG. 19 depicts a divided phase winding circuit with a tap from thedivided phase winding coil to the direct current (DC) power supply andtwo power switches in parallel.

FIG. 20 depicts a motor with a divided phase winding circuit having aprimary AC phase winding and secondary winding to create anon-collapsing DC power supply.

FIG. 21 depicts a motor with a divided phase winding circuit having aprimary AC phase winding and secondary winding to create anon-collapsing DC power supply wound on only one pole.

FIG. 22 depicts a motor with a divided phase winding circuit with atapped primary phase winding to create a non-collapsing DC power supply.

FIG. 23 depicts a motor with a divided phase winding circuit withresisters to create a non-collapsing DC power supply.

FIG. 24 depicts a motor with a divided phase winding circuit with Zenerdiodes to create a non-collapsing DC power supply.

DETAILED DESCRIPTION

New and useful circuits are disclosed that provide advantages over theprior art for controlling synchronous brushless permanent magnet motors.One embodiment of the present disclosure includes one or more circuitsfor an electronically commutated motor (ECM). Another embodiment of thepresent disclosure includes one or more circuits for a shaded polemotor. In one aspect, a motor has multiple motor phases (i.e. motorphase windings) and a supply line voltage through the phases. The motorphases are divided in half and both the motor controller for the motorand the power electronics for the motor are placed at a “mid-point” or“center point” in the supply line voltage between the divided phases.The direct current (DC) power supply (e.g. for the electronics used inthe motor controller) are also located between the divided phases. Themotor phases provide current limiting and the voltage drop from the linevoltage supply lines to low voltage DC to the DC power supply, therebyreducing the DC power supply component count and allowing for the use oflow voltage components for the DC power supply and for the motorcontroller.

Prior systems used a Zener diode or other voltage regulator located inseries with a power switch and the motor phases, which limited themaximum power of the motor to the maximum wattage value of the Zenerdiode. Circuits in the present disclosure eliminate the Zener diodevoltage regulator from the primary current path for the motor phases sothat a Zener diode voltage regulator is not located in series with apower switch and the motor phases, which eliminates the need to lowerthe wattage specification otherwise needed for a Zener diode. Instead,the Zener diode or other voltage regulator is located in parallel withthe power switch(es) in some embodiments of the present disclosure.

Circuits in the present disclosure eliminate the need for anopto-isolator to allow switching between sensing/control electronics ofa motor controller and a power switch of the motor controller. Priorsystems had two neutral reference values, one for sensing/controlelectronics and one for a power switch.

Circuits in the present disclosure have improved line phase angledetection, eliminating the need for a precision resistance bridge linkedto the input of an opto-isolator. Thus, the circuits of this aspect havemore accurate line phase angle detection.

Circuits in the present disclosure reduce different electrical neutralvalues for the power switches and motor controller to one value. Thisguarantees that the power switch(s) of the circuits with this aspectwill reliably transition from completely “off” to fully saturated.

Prior systems that included two switches have a difficult time turningone switch off completely for one half of an AC cycle. Circuits in thepresent disclosure place one or more switches outside of a DC powersupply and motor controller circuit, resulting in proper switching.

Each of these improvements not only increases the reliability of theoperation of the motor controller, but also serves to improve thecombined motor/motor controller efficiency.

The divided phase winding circuits in the present disclosure can be usedin a variety of motors, such as DC brushless motors/electronicallycommunicated motors (ECMs), shaded pole motors, other synchronousmotors, permanent-split capacitor (PSC) motors, etc.

For example, FIG. 1 depicts a motor 102 with divided motor phasewindings 104, 106 and a motor control circuit 108 located at a mid-point110 in the divided motor phase windings. The motor 102 includes a stator112 and a rotor 114 mounted on a shaft 116. The rotor 114 is mounted forrotation in a core structure, such as laminated core structure or othercore structure. The rotor 114 has a body portion which is shown ascylindrical in shape. Around the periphery of the body are locatedarcuately shaped permanent magnetic portions. The magnetic portion hasits north magnetic pole adjacent to the outer surface of the rotor andthe magnetic portion has its south magnetic pole located adjacent toouter periphery of the rotor 114. A winding or pair of windings aremounted on the connecting portion of the core structure. The motor 102also includes a Hall Effect switching device, a portion of which extendsto adjacent the periphery of the rotor 114 for responding to themagnetic polarity of the respective rotor magnetic portions. In theconstruction as shown, the Hall Effect switch is located adjacent theouter periphery of the magnetic portion during half of each revolutionof rotor 114 and adjacent the outer periphery of the magnetic portionduring the remaining half of each revolution of rotor.

The motor 102 can operate below, at, or above synchronous speeds. Thisis due to the fact that fractions of half cycles can flow through thephase windings.

The divided phase winding circuit of FIG. 1 includes input connectionson leads L1 and L2 connected to a source of alternating current (AC)energy during operation, such as AC line voltage. The leads L1 and L2are connected across a series circuit that includes divided phasewindings 104, 106 shown connected in series across a control circuit108. For example, the control circuit 108 may include a full wave dioderectifier bridge circuit connected in series to the divided phasewindings 104, 106 and a power switch(es) circuit having one or moreswitches or other power controllable switching devices connected to theoutput of the full wave diode rectifier bridge circuit.

The divided phase windings 104, 106 can be bifilar or lap wound. Thealternating current power source has its lead L1 connected to the startside S1 of the first winding 104. The other end of the winding 104,labeled F1, is connected to one of the inputs of the control circuit108. The other input side of the control circuit 108 is attached to thestart side S2 of the second divided phase winding 106 and the finishside of the same divided phase winding, labeled F2, is attached to theinput lead L2 of the AC power source.

As another example, FIG. 2 depicts a single phase ECM 202 in which themotor phase windings are divided and a motor controller (motor controlcircuit) is located at a mid-point in the divided motor phase windings.

FIG. 3 discloses a divided phase winding circuit 302 for dividing motorphase windings 304, 306 (also referred to as motor phases or phase coilsherein) of a motor in half and placing both a motor controller 308 forthe motor and power electronics for the motor, including the DC powersupply 310 and a power switch(es) circuit 312 with one or more powerswitches, at a “mid-point” or “center point” 314 in the supply linevoltage between the divided phases 304, 306. In the example of FIG. 3,the motor phase winding is divided in half. Some variation from the halfdivision is allowable, such as between zero and plus/minus 20% of thehalfway point.

The divided phase winding circuit 302 of FIG. 3 includes two dividedphase windings 304, 306, each connected to AC line voltage L1 and L2respectively. A DC power supply 310 is electrically connected to thedivided phase windings 304, 306, such as at the finish side of the firstphase winding 304 and the start side of the second phase winding 306.The divided phase winding 304, 306 operates to lower the AC line voltageto a voltage compatible with the DC power supply 310. Thus, the numberof windings in the divided phase winding 304, 306 can be selected toreduce the AC line voltage received at L1 and L2 to a selected lowervoltage to be received by the DC power supply 310. The divided phasewinding 304, 306 also operates to filter noise from the AC line voltagereceived at L1 and L2.

The DC power supply 310 converts the low voltage AC power received fromthe divided phase windings 304, 306 to a DC voltage configured to powerthe DC powered components of the divided phase winding circuit,including the motor controller 308. The DC power supply 310 thensupplies power to the motor controller 308.

The motor controller 308 controls the start-up and operation of thedivided phase winding circuit 302. For example, the motor controller 308controls start-up, including where the motor is a synchronous motor. Themotor controller 308 determines the location of the rotor relative tothe stator. The motor controller 308 also determines and monitors thespeed of the rotor, such as in revolutions per minute (RPMs), todetermine operational parameters of the motor, such as when the motorhas reached synchronous speed, and controls the motor based on thelocation of the rotor and or speed of the motor. In one example, themotor controller 308 has a Hall effect switch and/or other rotationdetermining device to determine the position of the rotor and/orrotation counting or speed determining device to determine the speed ofthe rotor.

The power switch(es) circuit 312 includes one or more power switches,such as one or more metal-oxide-semiconductor field-effect transistors(MOSFETs), silicon-controlled rectifiers (SCRs), transistors, or otherswitches or switching devices. The one or more switches are on or off orone is on while the other is off. For example, in one half cycle of anAC cycle, a first power switch is on and conducting while the secondswitch is off and not conducting. In the other half cycle of the ACcycle, the second power switch is on and conducting while the firstswitch is off and not conducting. In circuits with one switch, theswitch may be on and conducting or off and not conducting during one ormore portions of the AC cycle.

The power switch(es) circuit 312 is isolated from (outside of) the DCpower supply 310, which makes the divided phase winding circuit 302 morestable than circuits having the power switch(es) circuit within (and notisolated from) the DC power supply.

Normally, when the power switch(es) of a circuit turn on, there is onlya slight voltage drop through the power switch(es) due to the minorresistance of the power switch(es). Therefore, if the input voltage forthe DC power supply is developed by connecting the DC power supply leadsto both sides of a power switch (or power switches), this would resultin the DC power supply collapsing when the power switch is in an ‘on’state or not being able to receive power and power the DC components ofthe circuit. The divided phase winding circuit 302 includes one or morenon-collapsing DC power supply components 316, 318, including voltagedrop components or direct DC power supply powering components to createa non-collapsing DC power supply. Examples of non-collapsing DC powersupply components 316, 318 include a tap from the primary phase winding304, 306 electrically connected to the DC power supply 310, a secondaryphase coil winding connected to the DC power supply to power the powersupply, resistors between the divided phase windings and the powerswitch(es) circuit 312, one or more Zener diodes between the dividedphase windings and the power switch(es) circuit, or other components tocreate a voltage drop between the primary divided phase windings and thepower switch(es) circuit to prevent the power supply from collapsingwhen the power switch(es) in the power switch(es) circuit is/are on andconducting. The divided phase winding circuit 302 therefore provides aconstant flow of power regardless of whether the power switch(es)circuit is on and conducting or off and not conducting.

Many electronically controlled synchronous motors have circuits thatdetect the zero crossing of the AC voltage applied to the phasewindings. This zero crossing detection circuit sends a signal to themotor controller 308 to determine when the motor is at synchronousspeed. If the AC supply voltage has electrical noise riding on, usuallydue to other equipment operating on the same circuit, this electricalnoise can cause the zero crossing detector to operate incorrectlyaffecting the control of the motor which normally appears as acousticalnoise in the motor.

In one example, the divided phase winding circuit 302 is part of asynchronous motor. The synchronous motor receives line power (that is,AC power) at L1 and L2. In a synchronous motor using a divided phasewinding using the associated circuit of the present disclosure does notrely upon detecting the zero crossing of the applied AC voltage tocontrol the motor but rather detects the polarity of the voltage, i.e.whether the polarity L2 is higher or less than L1 allowing for quietoperation even when electrical noise is present in the AC supply.

The DC power supply 310 in FIG. 3 is electrically connected directly tothe divided phase windings 304, 306. Thus, the DC power supply 310 ispowered by the divided phase windings 304, 306 regardless of the statusof the power switch(es) circuit 312.

FIG. 4 discloses another divided phase winding circuit 402 for dividingmotor phase windings 404, 406 of a motor in half and placing both amotor controller 408 for the motor and power electronics for the motor,including the DC power supply 410 and a power switch(es) circuit 412with one or more power switches, at a “mid-point” or “center point” 414in the supply line voltage between the divided phases. The divided phasewinding circuit 402 of FIG. 4 includes a tap 416, 418 from the primarydivided phase winding 404, 406 electrically connected to the DC powersupply 410 to create a non-collapsing DC power supply.

In some circuits, when the motor reaches synchronous speed, the one ormore power switch(es) turn off and thereby cause the low voltage powerto stop flowing to the motor controller. In one example, the path fromone divided phase winding through the power switch(es) to anotherdivided phase winding is shorted, such as at synchronous speed,resulting the DC power supply and motor controller no longer receivingthe low power supply voltage from the phase windings, such as in theevent there is no capacitor to hold a charge during the short or acapacitor that is present is not large enough to hold enough chargeduring the short. The circuit 402 of FIG. 4 includes a tap 416, 418 fromthe coils of the phase windings 404, 406 to the DC power supply 410 sothat the low voltage power supply flows directly from the phase windingsto the DC power supply, bypassing the power switch(es) (“divided motorphase controller”). The circuit 402 of FIG. 4 thereby guarantees thatthe low voltage power supply is supplied to the DC power supply 410, forexample at synchronous speed.

In one example, a DC power supply 410 for a divided motor phasecontroller is formed by a Zener diode and a storage capacitor thatreceives power during a portion of an alternating current (AC) cyclewhen the power switch(es) are off. When the motor is operating atsynchronous speed, the power switch(es) are continuously conducting.Therefore, the amount of voltage being supplied to the DC power supplyis equal to the voltage drop across the switch(es), which can result ina low voltage when using low on resistance (RDS(on)) power MOSFETs.

FIG. 5 discloses another divided phase winding circuit 502 for dividingmotor phase windings 504, 506 of a motor in half and placing both amotor controller 508 for the motor and power electronics for the motor,including the DC power supply 510 and a power switch(es) circuit 512with one or more power switches, at a “mid-point” or “center point” 514in the supply line voltage between the divided phases. The circuit 502of FIG. 5 includes resistors R1 and R2 between the motor phase windings504, 506 and the power switch(es) circuit 512 to hold up and thereforemaintain the low voltage power supply supplied from the phase windingsto the DC power supply 510 and create a non-collapsing DC power supply.The circuit of FIG. 5 thereby maintains the low voltage power supply tothe DC power supply 510, for example at synchronous speed.

FIG. 6 discloses another divided phase winding circuit 602 for dividingmotor phase windings 604, 606 of a motor in half and placing both amotor controller 608 for the motor and power electronics for the motor,including the DC power supply 610 and a power switch(es) circuit 612with one or more power switches, at a “mid-point” or “center point” 614in the supply line voltage between the divided phases. The primarydivided phase winding 604, 606 limits the current that can flow to theDC power supply 610 eliminating the need for current limiting componentsthat waste power. The divided phase winding circuit 602 of FIG. 6includes a secondary phase winding 616, 618 electrically connected tothe DC power supply 610 to create a non-collapsing DC power supply.

In one example, the power switch(es) circuit 612 includes a Zener diodeor other voltage regulator and a power switch in parallel. Whereas,prior systems included the power circuit in series with othercomponents. Because the power switch is in parallel with the Zener diodeand not in series, it can always be on. However, if the power switch isoff, current can still flow through the Zener diode.

The circuit of FIG. 6 includes one or more secondary coils (alsoreferred to as a secondary winding) 616, 618 that provide a low voltagepower supply to the DC power supply 610, such as when the motor is atstart-up. The one or more secondary coils 616, 618 also act as a highfrequency noise filter to filter out high frequency noise from the lowpower voltage supplied to the DC power supply 610.

The secondary winding 616, 618 may be distributed anywhere, such asevenly between the first and second divided phase windings 604, 606, allon one pole, or unevenly between the first and second divided phasewindings, such as a greater number of turns or coils on one secondarywinding than another secondary winding.

In the example of FIG. 6, the divided phase winding circuit 602 can turnoff the DC electronics, including the motor controller 608, when themotor is on and at synchronous speed. Thus, the motor controller 608 ofthe divided phase winding circuit 602 determines the speed of the motorand whether the motor is or is not at synchronous speed. For example,1800 RPM may be the synchronous speed for a motor with four stator poles(two north stator poles and two south stator poles). Every half ACcycle, power is supplied to one of the magnetic poles. Therefore, ittakes two cycles to provide power to the four magnetic poles. Thus, thesynchronous speed is 1800 RPM if the motor is synced to line AC.Similarly, the synchronous speed for an eight-pole stator would be 900RPMs.

FIG. 7 depicts a control of phase current direction during start up andcontinuous operation below synchronous speeds in a divided phase windingcircuit 702.

As shown in FIG. 7, the current will always flow across both dividedphase windings 704, 706 and control circuit in the same direction. Thedivided phase windings 704, 706, being in series with the controlcircuit, represent one winding with the control circuit placed at themid-point or center point between the divided phase windings. Thecurrent and voltage applied to the divided phase windings will always bein the same direction through both coils, and the magnetic polarity ofthe divided phase windings will likewise be the same.

As discussed below, the control circuit may include a diode rectifierbridge circuit whose output is connected to one or more power switches.As shown in FIG. 7, if the output terminals of the diode bridgerectifier of the control circuit are shorted when the voltage on lead L1is positive, the current will only flow through the winding 704, 706 inone direction, but in half cycle increments. If the voltage across leadsL1 and L2 is 60 cycles, then the outputs of the diode bridge rectifiercircuit in the control circuit will be shorted only when lead L1 ispositive, and current flow will flow only in one direction and for 8milliseconds. No current will flow for 8 milliseconds on the alternatehalf cycles. Then current would flow for another 8 milliseconds and soon. If the output of the diode bridge circuit of the control circuit isshorted when lead L2 is positive, then power will flow in exactly thesame manner. If the shorting of the output of the bridge is accomplishedselectively, that is based on the angular position of the magneticrotor, continuous motor action will be produced. If the diode bridgerectifier circuit output in the control circuit is shorted for afraction of a half cycle selectively based on the angular position ofthe magnetic rotor as described above, and only when lead L1 ispositive, then any desired speed can be accomplished including speedshigher than the synchronous speed. The characteristics of such a motorwould be similar to a DC motor with pulsating current applied to theinputs. However, rather than having multiple power switching componentsachieve the switching of the divided phase windings, the divided phasewinding circuit makes use of the fact that alternating current inconjunction with one power switching component can accomplish theswitching.

FIG. 8 depicts an example of control of phase current direction at asynchronous speed of 1800 revolutions per minute (RPM) in a four poledivided phase winding circuit. At synchronous speed, the controlledphase is synchronized with the AC line input.

FIG. 9 depicts a control of phase current direction at a synchronousspeed of 3600 revolutions per minute (RPM) in a two pole divided phasewinding circuit. At synchronous speed, the controlled phase issynchronized with the AC line input.

FIG. 10 depicts an example of DC power supply storage capacitor chargingperiods in a divided phase winding circuit. Note the correlation to thewave form of FIG. 7.

FIG. 11 depicts a divided phase winding circuit 1102 with a secondarycoil 1104, 1106 and one power switch 1108. The primary divided phasewinding 1110, 1112 limits the current that can flow to the DC powersupply.

The control circuit 1114 controls switching for the power switch(es)circuit based on timing of the input frequency and rotor position. Thecontrol circuit 1114 controls the start-up and operation of the dividedphase winding circuit. For example, the control circuit 1114 controlsstart-up, including where the motor is a synchronous motor. The controlcircuit 1114 determines the location of the rotor relative to thestator. The control circuit 1114 also determines and monitors the speedof the rotor, such as in revolutions per minute (RPMs), to determineoperational parameters of the motor, such as when the motor has reachedsynchronous speed, and controls the motor based on the location of therotor and or speed of the motor. In one example, the control circuit1114 has a Hall effect switch and/or other rotation determining deviceto determine the position of the rotor and/or rotation counting or speeddetermining device to determine the speed of the rotor.

In one example, the power switch(es) circuit includes a Zener diode 1116or other voltage regulator and a power switch 1108 in parallel. Whereas,prior systems included the power circuit in series with othercomponents. Because the power switch 1108 is in parallel with the Zenerdiode 1116 and not in series, it can always be on. However, if the powerswitch is off, current can still flow through the Zener diode.

The circuit of FIG. 11 includes one or more secondary coils (alsoreferred to as a secondary winding) 1104, 1106 that provide a lowvoltage power supply to the DC power supply, such as when the motor isat start-up. The one or more secondary coils 1104, 1106 also act as ahigh frequency noise filter to filter out high frequency noise from thelow power voltage supplied to the DC power supply.

The secondary winding 1104, 1106 may be distributed anywhere, such asevenly between the first and second divided phase windings 1110, 1112,all on one pole, or unevenly between the first and second divided phasewindings, such as a greater number of turns or coils on one secondarywinding than another secondary winding.

The way that the coils are connected to the circuit via the diode bridgerectifier 1118 allow for current to flow through the coils in only onedirection at any given time. The improvements that have been made tothis motor and controller greatly improve the DC logic power supplywhich enables a more reliable logic control circuit. Secondary coils1104, 1106 are wound with the motor coils in a method that creates atransformer using the motor coils as primary 1110, 1112.

The improvements that have been made to this motor and controllergreatly improve the DC logic power supply which enables a more reliablelogic control circuit. Secondary coils are wound with the motor coils ina method that creates a transformer using the motor coils as primary.The example of FIG. 11 uses a 20:1 ratio. The example of FIG. 11includes 1000 turns per motor primary coil and 50 turns per secondarycoil that are wound on the same stator pole. However, other turn ratiosmay be used, higher or lower. The ratio between the primary motor coils1110, 1112 and secondary coils 1104, 1106 may change with AC input powerand/or DC power requirements. This circuit not only isolates all DCcircuitry from high voltages from the line, but also creates anon-collapsible DC power supply to the control circuit when power isapplied to inputs L1 and L2.

The power switch(es) circuit consists of 2 main components, a full wavebridge rectifier 1118 and a MOSFET power switch 1108. The full wavebridge rectifier 1118 guarantees that no negative voltage will besupplied to the drain (top) of the power switch 1108. The full wavebridge rectifier 1118 also guarantees that no positive voltage will besupplied to the source (bottom) of the power switch 1108 so that currentcan only flow from the drain to the source of the power switch 1108 whenbiased by a positive voltage on the gate of the power switch 1108 viaresistor R1. Simultaneously, as a positive rectified AC power supply ispresent at the drain of the power switch 1108, the power switch 1108 isbiased by the same voltage signal via resistor R1. Diode 1116 protectsthe gate of the power switch 1108 by guaranteeing that any voltage onthe gate of the power switch 1108 will be greater than −0.7 VDC, asanything less could damage or destroy the power switch 1108. ResistorR11 and capacitor C5 are used as a “snubber” to filter out transients orhigh frequency noise. R11 and C5 provide added protection for the MOSFETpower switch 1108, especially in noisy environments.

FIG. 12 depicts a divided phase winding circuit 1202 with a secondarycoil 1104, 1106 and one power switch 1108. The circuit of FIG. 12includes the same power switch(es) circuit of FIG. 11 and the samesecondary coils 1104, 1106. In addition, the control circuit 1114A ofFIG. 12 includes a logic control circuit 1204 to control operation ofthe motor, including through synchronous speed, a logic control shut offcircuit 1206 to control when the power switch(es) circuit is turned off,and a non-collapsing DC power supply 1208 to supply DC power to thelogic control circuit and login control shut off circuit. The logiccontrol circuit 1204 and login control shut off circuit 1206 may beconfigured as a single logic control circuit.

In one embodiment, one purpose of this divided phase windings circuit1202 is to allow a motor to run synchronously to the AC power supplyline frequency (for example, for a 4 pole motor, 60 Hz=1800 rpm and 50Hz=1500 rpm). Without any control circuitry, the power switch(es)circuit would allow current to flow as if coil pairs L1 and L2 wereshorted together through the power switch(es) circuit. The controlcircuitry simply turns power switch(es) circuit off until the rotor isin the proper position compared to the line voltage. For this reason, inone aspect, the power switch(es) circuit is rated for the AC powersupply line voltage. The control circuitry components can all be at thelogic level voltage (VCC). Logic power is supplied by secondary coils1104, 1106 that are wound on the same poles as the primary motor coils1110, 1112. Secondary coils 1104, 1106 could be wound on any number ofpoles as long as the secondary power meets logic power requirements.Since the control circuit is only needed to start the motor and bring itto synchronous speed, the logic control shut off circuit optionally isincluded to shut off the main control circuit. The logic control shutoff circuit is optional. By shutting the control circuit off, the powerswitch(es) circuit will allow full line power to the motor minus anylosses in the power switch(es) circuit. This will increase totalefficiency and the life of components especially when the motor runs forlong periods.

FIGS. 13 and 13A depict a divided phase winding circuit with a secondarycoil and one power switch. The circuit has two AC supply line inputs L1and L2, which are connected to an AC power source during operation ofthe motor.

Power Switch

The Power Switch block consists of 2 main components, a full wave bridgerectifier BR1 and a MOSFET power switch Q1. The full wave bridgerectifier BR1 guarantees that no negative voltage will be supplied tothe drain (top) of the power switch Q1. The full wave bridge rectifierBR1 also guarantees that no positive voltage will be supplied to thesource (bottom) of the power switch Q1 so that current can only flowfrom the drain to the source of the power switch Q1 when biased by apositive voltage on the gate of the power switch Q1 via resistor R1.Simultaneously, as a positive rectified AC power supply is present atthe drain of the power switch Q1, the power switch Q1 is biased by thesame voltage signal via resistor R1. Diode D5 protects the gate of thepower switch Q1 by guaranteeing that any voltage on the gate of thepower switch Q1 will be greater than −0.7 VDC, as anything less coulddamage or destroy the power switch Q1. Resistor R11 and capacitor C5 areused as a “snubber” to filter out transients or high frequency noise.R11 and C5 provide added protection for the MOSFET power switch Q1,especially in noisy environments.

DC Power Supply

As soon as power is applied to the motor and current is flowing throughthe motor phase windings (motor primary coils), there is power on thesecondary windings (secondary coils) in the same manner as the operationof a transformer. The value of voltage on the secondary coils isdirectly proportional to the input voltage and the primary to secondaryturn count ratio. Using the example in FIG. 11, if the input voltage tothe primary coils is 120 VAC and the turn count ratio from primary tosecondary is 20:1, then the voltage on the secondary coils wouldcalculate to approximately 6 VAC minus any losses. Power from thesecondary coils is supplied directly from the secondary coils to the DCpower supply. The full wave bridge rectifier BR2 rectifies the lowvoltage AC power supply from the secondary coils. The full wave bridgerectifier BR2 can be a low power component based on the DC supplyrequirements.

Zener diodes Z1 and Z2 are connected in series with each other anode toanode, and each cathode is connected to the AC power supply inputs ofthe full wave bridge rectifier BR2. This method is used to protect thefull wave bridge rectifier BR2 from AC power supply inputs that couldexceed maximum ratings for the component. The negative output from thefull wave bridge rectifier BR2 is connected to the circuit ground, whichis also connected to the same ground as the power switch block. Thepositive output from the full wave bridge rectifier BR2 is connected tothe low drop-out regulator LDO1 and capacitor C1. Capacitor C1 isprovided to smooth the rectified AC power supply signal going to theinput of the low drop-out regulator LDO1. A bypass capacitor C7 could beused on the output of the low drop-out regulator LDO1 to help reducenoise on the positive DC rail (VCC). Also, a larger capacitor C10 couldbe used on the output of the low drop-out regulator LDO1 to smooth thepositive DC rail and ensure power during some low voltage situations. C7and C10 are not required but are provided to add reliability andprotection for low voltage DC components, especially in a noisyenvironment.

Logic Control

The control circuit controls switching for the power switch(es) circuitbased on timing of the AC supply line input frequency and rotorposition. Timing of the AC supply line input frequency is sensed usingan AC buffer that consists of bi-polar junction transistors (BJTs) Q2and Q3 and diodes D6 and D7. Current to the AC buffer input is limitedby a high value resistor R3. Diode D6 ensures that the AC buffer inputis not greater than the positive DC supply voltage. Diode D7 ensures theAC buffer input is greater than −0.7 volts referenced to the DC supplyground.

When the input to the AC buffer is logic high, BJT Q2 is biased, and theoutput of the AC buffer is also logic high. When the input to the ACbuffer is logic low, BJT Q3 is biased, and the output of the AC bufferis logic low. The output the AC buffer is connected to a filterconsisting of capacitor C6 and resistor R13. The filter is not requiredbut provides protection and reliability in noisy environments.

Rotor magnet polarity is sensed using Hall-effect switch IC1. Though,another switch or sensing device may be used to sense rotor magnetpolarity and/or rotor position and/or determine speed and/or determinerotor revolutions. The Hall-effect switch IC1 is an open-collectoroutput and therefore requires a pull-up to the positive DC rail (VCC).Resistor R2 provides the pull-up required for the open-collector output.

The output of the Hall-effect switch IC1 and the output of the AC bufferare compared using a single circuit logic XOR IC2. The output of the XORIC2 is the difference between the Hall-effect switch IC1 and the ACbuffer, which will bias MOSFET power switch Q1 of the power switch(es)circuit. When the Hall-effect switch IC1 output is logic low, the powerswitch Q1 will only be biased when the AC supply input L1 to the motoris negative. When the output of the Hall-effect switch IC1 is logichigh, the power switch Q1 will only be biased when the AC supply inputL1 to the motor is positive. During motor start up, there can bemultiple input AC cycles where either only the positive or only thenegative inputs from AC supply input L1 will pass through the powerswitch Q1.

Using the power switch Q1, waveforms can be “chopped” or shut off at anytime when the drain and gate voltage of the power switch Q1 is abovebiasing voltage. For example, see FIG. 7. The gate of the power switchQ1 is held logic low when the output of the XOR IC2 is logic high bybiasing BJT Q4. When BJT Q4 is biased, any current flowing from resistorR1 will bypass the gate of the power switch Q1 and flow through BJT Q4from collector to emitter electrically connecting the gate of the powerswitch Q1 to its source and will shut off the power switch Q1immediately.

When the frequency of the Hall-effect switch IC1 matches the frequencyof the input AC supply, the motor is running synchronously. If the motoris running synchronously, the control circuit is not needed until eitherthe motor falls out of sync or the motor is stopped and restarted. Whenthe frequency to voltage regulator IC3 senses synchronous speed orgreater from the Hall-effect switch IC1, the output of the XOR IC2 isheld logic low via the open-collector output of the voltage regulatorIC3. If the sensor speed is less than that of the input AC supply, theopen-collector output of the voltage regulator IC3 is off, which willleave the output of the XOR IC2 unaffected.

This method ensures that when the motor is running at a synchronousspeed, the power switch Q1 is not shut off by the logic control. But, ifthe motor slows down below synchronous speeds, then the logic controllerwill control the motor timing as it does for start-up. Using this methodimproves overall motor efficiency and the expected lifetime ofcomponents in the circuit.

External components are required to set timing for the voltage regulatorIC3. Resistors R4, R5, R6 and R7 may be 1% tolerance so that the voltageregulator IC3 operates within accurate parameters. Capacitor C1 operatesin conjunction with the resistors R6 and R7 to set the frequency atwhich the open-collector output of the voltage regulator IC3 will turnon. Capacitor C3 is used for an internal charge pump in the voltageregulator IC3. Capacitor C4 is used to AC couple the input to thevoltage regulator IC3 since the voltage regulator IC3 will only detectfrequencies that have a zero-voltage crossing. Resistor R8 limitscurrent to the AC couple C4 at the input of the voltage regulator IC3.

FIG. 14 depicts a divided phase winding circuit with two power switches.

FIG. 15 depicts a divided phase winding circuit with one power switch.

FIG. 16 depicts a divided phase winding circuit with two power switchesin series. Diodes D1 & D2 are 1N4003 and diodes D3 & D4 are 1N914.Transistors Q3 and Q4 are 2N3904. IC1 is a Hall-effect switch/sensor.Diodes D5 and D6 are used to increase the current capacity for theinternal diodes in switches Q1 and Q2 (d1 & d2) if the phase currentexceeds the internal diodes forward current rating. Capacitors C2 and C3are optional in one embodiment. Capacitors C2 and C3 are used to createa ‘turn on’ delay for switches Q1 and Q2 to add additional charge timefor capacitor C1 if necessary to insure a solid 3.3 VDC or 5 VDC supplyfor Hall switch/sensor IC1, depending upon the device choice for Hallswitch/sensor IC1. In prior systems, 5 VDC was necessary to switch onthe logic level power MOSFET switch.

Diodes D1, D2, d1, and d2 perform the rectification of the AC power forthe DC power supply for Hall switch/sensor IC1.

Zener diode ZD1 provides the voltage regulator for the Hallswitch/sensor IC1's DC supply.

RL provides current limiting for the DC power supply. It should be setto approximately limit the current to 10 mA. The Hall switch/sensor IC1uses 6 mA, including the base drive current for the internal opencollector output transistor. Additional DC current will be used toswitch Q3 and is supplied through the ‘pull up’ resistor R3. Thecollector to emitter current for switch Q3 and the base and collector toemitter current for switch Q4 is not supplied by the DC power supply butis supplied by the current through the motor phase windings. It ispreferable to assure that transistors Q3 and Q4 turn completely ‘off’ atthe proper times. It is preferred in one embodiment, but not arequirement, that the switches turn fully ‘on’ or in saturation at theproper times for maximum operational efficiency.

FIG. 17 depicts a divided phase winding circuit with a tap from thedivided phase winding coil to the direct current (DC) power supply andtwo power switches in series.

FIG. 18 depicts a divided phase winding circuit with two power switchesin parallel.

FIG. 19 depicts a divided phase winding circuit with a tap from thedivided phase winding coil to the direct current (DC) power supply andtwo power switches in parallel.

FIG. 20 depicts a motor with a divided phase winding circuit having aprimary AC phase winding and secondary winding to create anon-collapsing DC power supply. In the motor of FIG. 20, the secondarywinding is wound on all poles. However, the secondary winding can bewound on just one pole, two poles, three poles, or another number ofpoles. The secondary winding is connected in series with the primaryphase winding in the motor of FIG. 20. However, the secondary windingalso may be connected in parallel or with a combination of both seriesand parallel. The motor of FIG. 20 is a four pole permanent magnetsynchronous motor. The synchronous speed for the motor when operating at60 Hz AC is 1800 RPM.

FIG. 21 depicts a motor with a divided phase winding circuit having aprimary AC phase winding and secondary winding to create anon-collapsing DC power supply wound on only one pole. The motor of FIG.21 is a four pole permanent magnet synchronous motor. The synchronousspeed for the motor when operating at 60 Hz AC is 1800 RPM.

FIG. 22 depicts a motor 2202 with a divided phase winding circuit with atapped primary phase winding to create a non-collapsing DC power supply.The motor of FIG. 22 is a four pole permanent magnet synchronous motor.The synchronous speed for the motor when operating at 60 Hz AC is 1800RPM.

The motor has a stator 2204 with 4 poles 2206-2212 and a rotor 2214 with4 magnets N, S, N, S 2216-2222 facing the stator. The motor 2202 has ashaft (center circle) 2224 and rotor back iron (the area between theshaft and the magnets) 2226. The primary divided phase windings 2228,2230 are connected to an AC power supply at L1 and L2, respectively. Asecondary winding 2232, 2234 is connected to the DC power supply 2236.

FIG. 23 depicts a motor with a divided phase winding circuit 2302 withresisters 2304, 2306 between the divided phase windings 2308, 2310 andthe power switch(es) circuit 2312 to create a non-collapsing DC powersupply. The motor of FIG. 23 is a four pole permanent magnet synchronousmotor. The synchronous speed for the motor when operating at 60 Hz AC is1800 RPM.

FIG. 24 depicts a motor with a divided phase winding circuit 2402 withZener diodes 2404, 2406 between the divided phase windings 2408, 2410and the power switch(es) circuit 2412 to create a non-collapsing DCpower supply. The motor of FIG. 24 is a four pole permanent magnetsynchronous motor. The synchronous speed for the motor when operating at60 Hz AC is 1800 RPM.

Those skilled in the art will appreciate that variations from thespecific embodiments disclosed above are contemplated by the invention.The invention should not be restricted to the above embodiments, butshould be measured by the following claims.

What is claimed is:
 1. A circuit for a motor comprising: phase windingsdivided at least approximately in half; a direct current (DC) powersupply between the phase windings to receive alternating current (AC)power from the phase windings and convert the AC power to DC power; apower switch circuit comprising at least one power switch between thephase windings to receive AC power from the phase windings; a controlcircuit to control the power switch circuit, wherein the control circuitcomprises a logic control shut off circuit to shut off the controlcircuit when the motor is at synchronous speed; and at least onenon-collapsing DC power supply component connected to the DC powersupply to prevent the DC power supply from collapsing when the at leastone power switch is on during at least a portion of an AC cycle.
 2. Thecircuit of claim 1 wherein the at least one non-collapsing DC powersupply component comprises: a first non-collapsing DC power supplycomponent connected to the DC power supply to prevent the DC powersupply from collapsing when the at least one power switch is on during afirst portion of the AC cycle; and a second non-collapsing DC powersupply component connected to the DC power supply to prevent the DCpower supply from collapsing when the at least one power switch is onduring a second portion of the AC cycle.
 3. The circuit of claim 2wherein the non-collapsing DC power supply components each comprises atap from one of the phase windings to receive AC power from the one ofthe phase windings and supply the AC power to the DC power supply andbypass the power switch circuit.
 4. The circuit of claim 2 wherein thenon-collapsing DC power supply components each comprises a secondaryphase coil winding wound in relation to one of the phase windings toreceive AC power from the one of the phase windings and supply the ACpower to the DC power supply and bypass the power switch circuit.
 5. Thecircuit of claim 4 wherein the phase windings comprise a first phasewinding and a second phase winding, and the secondary phase coilwindings are distributed evenly between the first and second phasewindings or unevenly between the first and second phase windings.
 6. Thecircuit of claim 4 wherein the phase windings comprise a first phasewinding and a second phase winding, and the secondary phase coilwindings are distributed all on one pole or on more than one pole of thestator.
 7. The circuit of claim 1 wherein the at least onenon-collapsing DC power supply component comprises at least one of: atleast one tap from at least one of the phase windings to receive the ACpower from the at least one phase winding and supply the AC power to theDC power supply and bypass the power switch circuit; or at least onesecondary phase coil winding wound in relation to the at least one phasewinding to receive the AC power from the at least one phase winding andsupply the AC power to the DC power supply and bypass the power switchcircuit.
 8. The circuit of claim 1 wherein the at least onenon-collapsing DC power supply component comprises at least oneelectrical component to create a voltage drop between the phase windingsand the power switch circuit to prevent the DC power supply fromcollapsing when the at least one power switch in the power switchcircuit is on.
 9. The circuit of claim 1 further comprising a voltageregulator in parallel with the at least one power switch, whereincurrent flows through the voltage regulator when the at least one powerswitch is on and off.
 10. The circuit of claim 1 wherein the powerswitch circuit comprises a full wave bridge rectifier operably connectedto the at least one power switch to stop negative voltage from beingsupplied to a drain of the at least one power switch and to stoppositive voltage from being supplied to a source of the at least onepower switch so that current only flows from the drain to the source ofthe at least one power switch when the at least one power switch isbiased by a positive voltage on a gate of the at least one power switch.11. The circuit of claim 1 wherein the at least one non-collapsing DCpower supply component is located at least approximately at a midpointbetween the phase windings.
 12. The circuit of claim 1 wherein thecontrol circuit turns off the power switch circuit when a rotorassociated with the circuit is in an identified rotor position, rotormagnet polarity, or speed relative to AC line voltage received by thephase windings.
 13. The circuit of claim 1 wherein the at least onepower switch comprises a first power switch and a second power switch,wherein the first power switch is on while the second power switch isoff in one half of the AC cycle, and the second power switch is on whilethe first power switch is off in another half of the AC cycle.
 14. Thecircuit of claim 1 wherein the at least one power switch comprises atleast one of one power switch, two power switches in series, and twopower switches in parallel.
 15. The circuit of claim 1 furthercomprising the motor to house the circuit, the motor selected from atleast one of a DC brushless motor, an electronically commutated motor, ashaded pole motor, and a permanent split capacitor motor.
 16. Thecircuit of claim 1 further comprising the motor to house the circuit,wherein the motor can operate at synchronous speed, below synchronousspeed, and above synchronous speed.
 17. The circuit of claim 1 whereinthe at least one non-collapsing DC power supply component is connecteddirectly or indirectly to the DC power supply.
 18. A circuit for a motorcomprising: phase windings; a direct current (DC) power supply betweenthe phase windings; a power switch circuit comprising at least one powerswitch between the phase windings; a control circuit to control thepower switch circuit, wherein the control circuit comprises a logiccontrol shut off circuit to shut off the control circuit when the motoris at synchronous speed; and at least one non-collapsing DC power supplycomponent to prevent the DC power supply from collapsing when the atleast one power switch is on during at least a portion of a cycle. 19.The circuit of claim 18 wherein the at least one non-collapsing DC powersupply component comprises: a first non-collapsing DC power supplycomponent to prevent the DC power supply from collapsing when the atleast one power switch is on during a first portion of the cycle; and asecond non-collapsing DC power supply component to prevent the DC powersupply from collapsing when the at least one power switch is on during asecond portion of the cycle.
 20. The circuit of claim 19 wherein thenon-collapsing DC power supply components each comprises a tap from oneof the phase windings to receive alternating current (AC) power from theone of the phase windings and supply the AC power to the DC power supplyand bypass the power switch circuit.
 21. The circuit of claim 19 whereinthe non-collapsing DC power supply components each comprises a secondaryphase coil winding wound in relation to one of the phase windings toreceive alternating current (AC) power from the one of the phasewindings and supply the AC power to the DC power supply and bypass thepower switch circuit.
 22. The circuit of claim 18 wherein the at leastone non-collapsing DC power supply component comprises at least one of:at least one tap from at least one of the phase windings to receivealternating current (AC) power from the at least one phase winding andsupply the AC power to the DC power supply and bypass the power switchcircuit; or at least one secondary phase coil winding wound in relationto the at least one phase winding to receive AC power from the at leastone phase winding and supply the AC power to the DC power supply andbypass the power switch circuit.
 23. The circuit of claim 18 wherein thecontrol circuit turns off the power switch circuit when a rotorassociated with the circuit is in an identified rotor position, rotormagnet polarity, or speed relative to AC line voltage received by thephase windings.
 24. A circuit for a motor comprising: phase windings toreceive alternating current (AC) power; a direct current (DC) powersupply between the phase windings to receive the AC power from the phasewindings and convert the AC power to a DC power; a power switch circuitcomprising at least one power switch between the phase windings; acontrol circuit to control the power switch circuit, wherein the controlcircuit comprises a logic control shut off circuit to shut off thecontrol circuit when the motor is at synchronous speed; and at least onenon-collapsing DC power supply component to prevent the DC power supplyfrom collapsing when the at least one power switch is on during at leasta portion of a cycle.
 25. A method for a circuit for a motor comprising:providing phase windings divided at least approximately in half;providing a direct current (DC) power supply between the phase windingsto receive alternating current (AC) power from the phase windings andconvert the AC power to DC power; providing a power switch circuitcomprising at least one power switch between the phase windings toreceive AC power from the phase windings; providing a control circuit tocontrol the power switch circuit, wherein the control circuit comprisesa logic control shut off circuit to shut off the control circuit whenthe motor is at synchronous speed; and providing at least onenon-collapsing DC power supply component connected to the DC powersupply to prevent the DC power supply from collapsing when the at leastone power switch is on during at least a portion of an AC cycle.
 26. Themethod of claim 25 wherein providing the at least one non-collapsing DCpower supply component comprises: providing a first non-collapsing DCpower supply component connected to the DC power supply to prevent theDC power supply from collapsing when the at least one power switch is onduring a first portion of the AC cycle; and providing a secondnon-collapsing DC power supply component connected to the DC powersupply to prevent the DC power supply from collapsing when the at leastone power switch is on during a second portion of the AC cycle.
 27. Themethod of claim 26 wherein providing the non-collapsing DC power supplycomponents comprises providing, for each non-collapsing DC power supplycomponent, a tap from one of the phase windings to receive AC power fromthe one of the phase windings and supply the AC power to the DC powersupply and bypass the power switch circuit.
 28. The method of claim 26wherein providing the non-collapsing DC power supply componentscomprises providing, for each non-collapsing DC power supply component,a secondary phase coil winding wound in relation to one of the phasewindings to receive AC power from the one of the phase windings andsupply the AC power to the DC power supply and bypass the power switchcircuit.
 29. The method of claim 28 wherein the phase windings comprisea first phase winding and a second phase winding, and the methodcomprises distributing the secondary phase coil windings evenly betweenthe first and second phase windings or unevenly between the first andsecond phase windings.
 30. The method of claim 28 wherein the phasewindings comprise a first phase winding and a second phase winding, andthe method comprises distributing the secondary phase coil windings allon one pole or on more than one pole of the stator.
 31. The method ofclaim 25 wherein providing the at least one non-collapsing DC powersupply component comprises at least one of: providing at least one tapfrom at least one of the phase windings to receive the AC power from theat least one phase winding and supply the AC power to the DC powersupply and bypass the power switch circuit; or providing at least onesecondary phase coil winding wound in relation to the at least one phasewinding to receive the AC power from the at least one phase winding andsupply the AC power to the DC power supply and bypass the power switchcircuit.
 32. The method of claim 25 wherein providing the at least onenon-collapsing DC power supply component comprises providing at leastone electrical component to create a voltage drop between the phasewindings and the power switch circuit to prevent the DC power supplyfrom collapsing when the at least one power switch in the power switchcircuit is on.
 33. The method of claim 25 further comprising providing avoltage regulator in parallel with the at least one power switch,wherein current flows through the voltage regulator when the at leastone power switch is on and off.
 34. The method of claim 25 furthercomprising providing the power switch circuit comprising a full wavebridge rectifier operably connected to the at least one power switch tostop negative voltage from being supplied to a drain of the at least onepower switch and to stop positive voltage from being supplied to asource of the at least one power switch so that current only flows fromthe drain to the source of the at least one power switch when the atleast one power switch is biased by a positive voltage on a gate of theat least one power switch.
 35. The method of claim 25 further comprisingproviding the at least one non-collapsing DC power supply component atleast approximately at a midpoint between the phase windings.
 36. Themethod of claim 25 further comprising providing the control circuit toturn off the power switch circuit when a rotor associated with thecircuit is in an identified rotor position, rotor magnet polarity, orspeed relative to AC line voltage received by the phase windings. 37.The method of claim 25 further comprising providing the at least onepower switch comprising a first power switch and a second power switch,wherein the first power switch is on while the second power switch isoff in one half of the AC cycle, and the second power switch is on whilethe first power switch is off in another half of the AC cycle.
 38. Themethod of claim 25 further comprising providing the at least one powerswitch comprising at least one of one power switch, two power switchesin series, and two power switches in parallel.
 39. The method of claim25 further comprising providing the motor to house the circuit, themotor selected from at least one of a DC brushless motor, anelectronically commutated motor, a shaded pole motor, and a permanentsplit capacitor motor.
 40. The method of claim 25 further comprisingproviding the motor to house the circuit, wherein the motor can operateat synchronous speed, below synchronous speed, and above synchronousspeed.
 41. The method of claim 25 further comprising connecting the atleast one non-collapsing DC power supply component directly orindirectly to the DC power supply.
 42. A method for a circuit for amotor comprising: providing phase windings; providing a direct current(DC) power supply between the phase windings; providing a power switchcircuit comprising at least one power switch between the phase windings;providing a control circuit to control the power switch circuit, whereinthe control circuit comprises a logic control shut off circuit to shutoff the control circuit when the motor is at synchronous speed; andproviding at least one non-collapsing DC power supply component toprevent the DC power supply from collapsing when the at least one powerswitch is on during at least a portion of a cycle.
 43. The method ofclaim 42 wherein providing the at least one non-collapsing DC powersupply component comprises: providing a first non-collapsing DC powersupply component to prevent the DC power supply from collapsing when theat least one power switch is on during a first portion of the cycle; andproviding a second non-collapsing DC power supply component to preventthe DC power supply from collapsing when the at least one power switchis on during a second portion of the cycle.
 44. The method of claim 43wherein providing the non-collapsing DC power supply componentscomprises providing, for each non-collapsing DC power supply component,a tap from one of the phase windings to receive alternating current (AC)power from the one of the phase windings and supply the AC power to theDC power supply and bypass the power switch circuit.
 45. The method ofclaim 43 wherein providing the non-collapsing DC power supply componentscomprises providing, for each non-collapsing DC power supply component,a secondary phase coil winding wound in relation to one of the phasewindings to receive alternating current (AC) power from the one of thephase windings and supply the AC power to the DC power supply and bypassthe power switch circuit.
 46. The method of claim 42 wherein providingthe at least one non-collapsing DC power supply component comprises atleast one of: providing at least one tap from at least one of the phasewindings to receive alternating current (AC) power from the at least onephase winding and supply the AC power to the DC power supply and bypassthe power switch circuit; or providing at least one secondary phase coilwinding wound in relation to the at least one phase winding to receiveAC power from the at least one phase winding and supply the AC power tothe DC power supply and bypass the power switch circuit.
 47. The methodof claim 42 further comprising providing the control circuit to turn offthe power switch circuit when a rotor associated with the circuit is inan identified rotor position, rotor magnet polarity, or speed relativeto AC line voltage received by the phase windings.
 48. A method for acircuit for a motor comprising: providing phase windings to receivealternating current (AC) power; providing a direct current (DC) powersupply between the phase windings to receive the AC power from the phasewindings and convert the AC power to a DC power; providing a powerswitch circuit comprising at least one power switch between the phasewindings; providing a control circuit to control the power switchcircuit, wherein the control circuit comprises a logic control shut offcircuit to shut off the control circuit when the motor is at synchronousspeed; and providing at least one non-collapsing DC power supplycomponent to prevent the DC power supply from collapsing when the atleast one power switch is on during at least a portion of a cycle.